Electrolyte preparation method and battery

Abstract

The invention discloses an electrolyte preparation method and a battery. The preparation method of the electrolyte comprises the following steps: adding a polymer and industrial solid waste into a solvent to form a mixed solution; preparing the mixed solution into a framework material; mixing a monomer, a lithium salt and an initiator to form a polymerization solution; and preparing the polymer solution and the framework material into the electrolyte. The method can realize high-value utilization of industrial solid wastes.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to an electrolyte preparation method and a battery. Background Art

[0002] With the development of industrial production, the amount of industrial solid waste is increasing. However, due to the wide variety and complex composition of industrial solid waste, its treatment is relatively difficult. For example, existing technologies can only produce industrial solid waste into construction materials such as cement, concrete aggregate, bricks and tiles, fiber, and cast stone, or agricultural materials such as fertilizers and soil conditioners, but cannot achieve high-value utilization of industrial solid waste.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Invention

[0004] One purpose of this application is to provide a new technical solution for an electrolyte preparation method and a battery.

[0005] According to a first aspect of the present application, a method for preparing an electrolyte is provided, comprising:

[0006] adding polymer and industrial solid waste to a solvent to form a mixed solution;

[0007] preparing the mixed solution into a skeleton material;

[0008] Mixing monomers, lithium salts, and initiators to form a polymerization solution;

[0009] The polymer solution and the skeleton material are prepared into an electrolyte.

[0010] Optionally, the solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran and formic acid;

[0011] The polymer comprises at least one of polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polyethylene oxide and polyvinyl alcohol;

[0012] The industrial solid waste includes at least one of slag, fly ash and metakaolin;

[0013] The mass ratio of the polymer to the industrial solid waste is 5:1 to 1:30.

[0014] Optionally, the mass fraction of the polymer in the mixed solution is 8% to 25%.

[0015] Optionally, the mixing temperature of the polymer and the industrial solid waste is 25 to 60° C.;

[0016] The mixing time of the polymer and the industrial solid waste is greater than or equal to 10 minutes.

[0017] Optionally, preparing the mixed solution into a skeleton material comprises:

[0018] The mixed solution is prepared into a first composite membrane using an electrospinning device;

[0019] The solvent in the first composite film is removed to form a skeleton material.

[0020] Optionally, the spinning voltage of the electrospinning device is 8 to 25 kV; the spinning flow rate of the electrospinning device is 1 to 1.5 ml / h; the distance between the spinning needle of the electrospinning device and the receiving device is 10 to 20 cm;

[0021] The thickness of the first composite film ranges from 5 to 100 μm;

[0022] The processing temperature for removing the solvent in the first composite film is 25-70°C.

[0023] Optionally, preparing the mixed solution into a skeleton material comprises:

[0024] coating the mixed solution on a carrier device using a coating process to prepare a second composite film;

[0025] The solvent in the second composite membrane is removed to form a skeleton material.

[0026] Optionally, the carrying device includes at least one of a polytetrafluoroethylene plate and a polytetrafluoroethylene disc;

[0027] The thickness of the second composite film ranges from 5 to 100 μm;

[0028] The processing temperature for removing the solvent in the second composite film is 25-70°C.

[0029] Optionally, the monomer includes at least one of polyethylene glycol acrylate and polyvinylene carbonate;

[0030] The lithium salt comprises at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium chloride and lithium nitrate;

[0031] The initiator comprises at least one of azobisisobutyronitrile and benzoyl peroxide;

[0032] The mass ratio of the monomer, the lithium salt and the initiator is 100-300:25-100:0.1-6.

[0033] According to a second aspect of the present invention, a battery is provided, wherein the battery comprises an electrolyte prepared by the electrolyte preparation method according to any one of the first aspects.

[0034] The electrolyte preparation method in the present application first adds a polymer and industrial solid waste to a solvent to form a mixed solution, and prepares the mixed solution into a skeleton material; then the skeleton material is mixed with a monomer, a lithium salt and an initiator to form a polymer solution to prepare an electrolyte, effectively realizing the high-value utilization of industrial solid waste.

[0035] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0037] Figure 1 1 is a flow chart of a method for preparing an electrolyte in one embodiment of the present invention.

[0038] Figure 2 Schematic diagram of the structure of the skeleton material in one embodiment of the present invention.

[0039] Figure 3 1 is a diagram of the cycle stability and coulombic efficiency of a battery in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0041] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0042] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0043] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0044] like Figure 1 As shown, the electrolyte preparation method in this application includes the following steps S101 to S104:

[0045] S101, adding a polymer and industrial solid waste to a solvent to form a mixed solution;

[0046] It should be noted that the embodiments of the present application apply industrial solid waste to the preparation of electrolytes, that is, innovatively add industrial solid waste to polymers, so that the inorganic nanoparticles in the industrial solid waste can be mixed with the polymer to form part of the battery's electrolyte, effectively realizing the high-value utilization of industrial solid waste.

[0047] Among them, since inorganic nanoparticles such as SiO2, ZrO2, TiO2, Al2O3, zeolite and montmorillonite (MMT) in industrial solid waste can reduce the crystallization ability of polymers and improve the chain segment mobility and ion conductivity of polymers, the present application adds polymers and industrial solid waste to a solvent to form a mixed solution, and prepares the mixed solution into a skeleton material, and then prepares the polymerization solution and skeleton material formed by mixing monomers, lithium salts, and initiators into an electrolyte, which can improve the electrical conductivity and mechanical properties of the electrolyte through the synergistic effect of the substance formed after monomer polymerization or the polymer formed after monomer polymerization and the inorganic nanoparticles.

[0048] In addition, since the skeleton material provided in the embodiment of the present application is prepared with a polymer as the matrix and a certain proportion of inorganic nanoparticles added, in order to fully mix the polymer and industrial solid waste and make the skeleton material more uniform, it is necessary to mix the polymer and industrial solid waste in a solvent.

[0049] In one embodiment, the solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, and formic acid.

[0050] Specifically, in order to further improve the uniformity of the framework material, it is preferred that the solvent include at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran and formic acid.

[0051] In one embodiment, the polymer includes at least one of polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polyethylene oxide, and polyvinyl alcohol.

[0052] Specifically, since the electrolyte provided in the embodiment of the present application is based on a polymer matrix and a certain proportion of inorganic nanoparticles is added to form a skeleton material, which is then in situ polymerized with a polymerization solution containing a monomer to form an organic / inorganic composite electrolyte, in order to make the electrolyte have excellent flexibility and film-forming properties, low interfacial impedance, and a sufficiently high Young's modulus to suppress lithium dendrites, the polymer preferably includes at least one of polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polyethylene oxide, and polyvinyl alcohol. The monomer preferably includes at least one of polyethylene glycol acrylate and polyvinyl carbonate;

[0053] In one embodiment, the industrial solid waste includes at least one of slag, fly ash, and metakaolin.

[0054] Specifically, since silica and alumina can effectively reduce the crystallization ability of polymers, so that the subsequently prepared electrolyte has higher electrical conductivity and mechanical properties, industrial solid waste with higher silica and alumina contents is preferred.

[0055] For example, the industrial solid waste may be at least one of slag, fly ash or metakaolin. Among them, the main chemical components of slag include silicon dioxide (content of 40% to 60%, which is one of the main components of slag), aluminum oxide (content of 15% to 30%), calcium oxide (content of 20% to 40%), magnesium oxide (content of 5% to 10%), iron oxide (content of 5% to 10%) and a small amount of sulfides such as CaS and MnS; the main chemical components of fly ash include silicon dioxide (content of 40% to 60%, which is the most important component of fly ash), aluminum oxide (content of 20% to 35%), iron oxide (content of 5% to 10%), calcium oxide (content of 2% to 5%), magnesium oxide (content of 0.5% to 2.5%) and sulfur trioxide (content is usually less than 2%); the main chemical components of metakaolin include silicon dioxide (content of 45% to 55%), aluminum oxide (content of 35% to 45%) and a small amount of iron oxide.

[0056] Of course, in other embodiments, the industrial solid waste may also be blast furnace slag, steel slag, red mud, non-ferrous metal slag, coal slag, sulfuric acid slag, waste gypsum, desulfurization ash, carbide slag, salt mud, tailings or mining waste rock, etc. Those skilled in the art may make a choice according to actual needs, and this application does not impose any specific restrictions here.

[0057] In one embodiment, the mass ratio of the polymer to the industrial solid waste is 5:1 to 1:30.

[0058] Specifically, the embodiment of the present application sets the mass ratio of polymer to industrial solid waste to 5:1 to 1:30, which can effectively improve the ionic conductivity, mechanical properties and processing properties of the subsequently prepared electrolyte and reduce the cost of electrolyte manufacturing.

[0059] For example, when the quality of the polymer is relatively high, the subsequently prepared electrolyte can have excellent flexibility and film-forming properties, as well as low interfacial impedance. When the quality of industrial solid waste is relatively high, the inorganic nanoparticles not only have a high Young's modulus and hardness, which can significantly improve the mechanical stability of the polymer electrolyte, thereby inhibiting the growth of lithium dendrites, but also improve the thermal stability of the polymer electrolyte, allowing it to maintain good performance in high-temperature environments. In addition, the inorganic nanoparticles in industrial solid waste can also reduce the crystallinity of the polymer formed during the polymerization of monomers in the polymerization solution, increase the amorphous region of the polymer, thereby improving the mobility of the chain segments and providing more migration paths for lithium ions.

[0060] In one embodiment, the mass fraction of the polymer in the mixed solution is 8% to 25%.

[0061] Specifically, since less or more polymer will affect the structure and properties of the subsequently prepared skeleton material, the more polymer there is, the thicker the fibers of the skeleton material prepared by electrospinning will be. Therefore, in order to make the prepared skeleton material have higher strength and toughness, the embodiment of the present application preferably has a mass fraction of the polymer of 8% to 25% of the mixed solution.

[0062] In one embodiment, the polymer and industrial solid waste may be blended to form a mixed solution, so that the mixed solution has higher uniformity, applicability and controllability.

[0063] Specifically, in the embodiment of the present application, one or more polymers may be first prepared into a polymer solution, and then industrial solid waste may be added to the polymer solution as an inorganic filler. Finally, stirring may be used to fully mix the polymer and industrial solid waste to form a mixed solution.

[0064] Therefore, the embodiment of the present application uses the solution blending method to not only make the mixed solution have higher uniformity, applicability and controllability, but also make the subsequently prepared electrolyte have higher electrical conductivity and mechanical properties.

[0065] In one embodiment, the polymer and industrial solid waste are mixed in a mixer to form a mixed solution; wherein the mixing temperature of the mixer is 25 to 60° C., and the mixing time of the mixer is greater than or equal to 10 minutes.

[0066] Specifically, the embodiment of the present application mixes the polymer and industrial solid waste through the mixer, so that the inorganic nanoparticles in the industrial solid waste can be evenly dispersed in the mixed solution. In this way, not only the mixing quality of the mixed solution is effectively improved, but also the ionic conductivity of the electrolyte is improved, the crystallization ability of the polymer formed when the monomers in the polymerization solution are reduced, and the chain segment mobility and ion conductivity of the polymer are improved.

[0067] In order to ensure the mixing quality of the mixed solution, the mixing temperature of the mixer is preferably 25-60° C., and the mixing time of the mixer is greater than or equal to 10 minutes.

[0068] Of course, in other embodiments, the polymer and industrial solid waste can also be mixed by magnetic stirring, as long as the mixing temperature can be guaranteed to be 25-60°C and the mixing time is greater than or equal to 10 minutes. Those skilled in the art can make a choice according to actual needs, and this application does not make any specific restrictions here.

[0069] S102, preparing the mixed solution into a skeleton material;

[0070] It should be noted that the embodiment of the present application can provide a channel for rapid transmission of lithium ions by preparing the mixed solution into a skeleton material, thereby effectively improving the ionic conductivity of the electrolyte; on the other hand, it can also improve the mechanical strength of the electrolyte, prevent the short circuit problem caused by the growth of lithium dendrites during the battery charging and discharging process, and can also enhance the toughness and fatigue resistance of the electrolyte; on the other hand, it can also improve the interface compatibility between the electrolyte and the electrode, reduce the interface resistance, and can also regulate the deposition behavior of lithium ions on the electrode to improve the interface stability.

[0071] In one embodiment, preparing the mixed solution into the skeleton material includes: using an electrospinning device to prepare the mixed solution into a first composite film; and removing the solvent in the first composite film to form the skeleton material.

[0072] Specifically, the embodiment of the present application can first prepare the mixed solution into a first composite film through an electrospinning device, then remove the solvent in the first composite film to form a skeleton material, and finally cut the skeleton material into a suitable shape according to the shape of the battery to facilitate subsequent packaging into a battery.

[0073] Among them, the electrospinning equipment can be used to prepare a nanofiber composite membrane with a porous three-dimensional conductive network structure with a high specific surface area and high porosity. The composite membrane with this structure has high ion transmission performance and adsorption capacity on the one hand. For example, in the battery, the first composite membrane with high porosity can increase the liquid absorption rate of the electrolyte and improve the ionic conductivity; on the other hand, it also has high mechanical strength and flexibility. For example, the composite membrane prepared with polyacrylonitrile as the matrix has a mechanical strength of up to 3.12MPa and can maintain dimensional integrity even at 200°C. Moreover, this high-strength composite membrane can effectively inhibit the growth of lithium dendrites in the battery, thereby improving the safety and cycle stability of the battery; on the other hand, it also has high thermal stability. For example, the composite membrane prepared with polyacrylonitrile as the matrix has a shrinkage rate of less than 5% after being heated at 200°C for 1h.

[0074] In addition, the shape of the skeleton material can be cut according to the shape of the battery. For example, the shape of the skeleton material can be circular, square or rectangular, etc. Those skilled in the art can choose according to actual needs, and this application does not make any specific restrictions here.

[0075] In one embodiment, the spinning voltage of the electrospinning device is 8 to 25 kV; the spinning flow rate of the electrospinning device is 1 to 1.5 ml / h; the distance between the spinning needle of the electrospinning device and the receiving device is 10 to 20 cm; the thickness range of the first composite membrane is 5 to 100 μm; and the processing temperature for removing the solvent in the first composite membrane is 25 to 70°C.

[0076] Specifically, the spinning voltage, spinning flow rate, and distance between the needle and the receiving device (device for receiving the first composite membrane) of the electrospinning equipment described in the embodiment of the present application can be adjusted according to the polymer and the spinning state, so as to improve the preparation efficiency of the electrospinning equipment.

[0077] For example, in order to improve the preparation efficiency of the first composite membrane, the spinning voltage of the electrospinning device is preferably 8 to 25 kV, the spinning flow rate of the electrospinning device is preferably 1 to 1.5 ml / h, the distance between the spinning needle of the electrospinning device and the receiving device is preferably 10 to 20 cm, and the processing time of the electrospinning device is 1 to 4 hours.

[0078] In order to ensure the adaptability of the first composite film, the thickness of the first composite film is preferably 5 to 100 μm.

[0079] In addition, the electrospinning equipment also includes a drying component, which can remove the solvent in the first composite film to form a skeleton material at room temperature, or the drying component can also be an oven to remove the solvent in the first composite film to form a skeleton material in an oven with a processing temperature of 40 to 70°C.

[0080] In one embodiment, preparing the mixed solution into the skeleton material includes: coating the mixed solution on a carrier device using a coating process to prepare a second composite film; and removing the solvent in the second composite film to form the skeleton material.

[0081] Specifically, in the embodiment of the present application, the solvent in the second composite film may be removed by volatilization to form a skeleton material, and then the skeleton material may be cut into a suitable shape according to the shape of the battery to facilitate subsequent packaging into a battery.

[0082] Among them, the embodiment of the present application adopts the volatilization method. On the one hand, it can accurately control the nanostructure of the prepared second composite membrane. For example, by adjusting the solution concentration, solvent volatilization rate and environmental conditions, a second composite membrane with uniform size and morphology can be prepared; on the other hand, a second composite membrane with a porous structure can also be formed. For example, a rich pore structure can be formed by the volatilization method, so that the prepared second composite membrane has a higher specific surface area and adsorption performance; on the other hand, the nanoparticles in the second composite membrane can be kept uniformly distributed to avoid agglomeration, thereby making the second composite membrane have higher mechanical and electrical properties.

[0083] In addition, the shape of the skeleton material can be cut according to the shape of the battery. For example, the shape of the skeleton material can be circular, square or rectangular, etc. Those skilled in the art can choose according to actual needs, and this application does not make any specific restrictions here.

[0084] In one embodiment, the supporting device includes at least one of a polytetrafluoroethylene plate and a polytetrafluoroethylene disk; the thickness of the second composite film ranges from 5 to 100 μm; and the processing temperature for removing the solvent from the second composite film is 25 to 70° C.

[0085] Specifically, since the polytetrafluoroethylene plate and the polytetrafluoroethylene disk do not react with the solvent in the mixed solution, the embodiment of the present application effectively improves the preparation efficiency of the second composite membrane by arranging the supporting device to include at least one of the polytetrafluoroethylene plate and the polytetrafluoroethylene disk.

[0086] In order to ensure the adaptability of the second composite film, the thickness of the second composite film is preferably 5 to 100 μm.

[0087] In addition, the supporting device can remove the solvent in the second composite film at room temperature to form the skeleton material, or can remove the solvent in the second composite film in an oven to form the skeleton material.

[0088] For example, after the mixed solution is coated on a polytetrafluoroethylene plate or a polytetrafluoroethylene disk, the polytetrafluoroethylene plate or the polytetrafluoroethylene disk is placed in an oven at 40-70° C. to remove the solvent in the second composite film to form a skeleton material.

[0089] S103, mixing monomers, lithium salt and initiator to form a polymerization solution;

[0090] It should be noted that since the present application uses industrial solid waste to prepare the skeleton material of the electrolyte, it is easy to cause insufficient stability of the electrolyte and electrode interface. In order to solve the above problem, the embodiment of the present application also mixes the monomer, lithium salt and initiator to form a polymerization solution, so that the polymerization solution can undergo an in situ polymerization mechanism with the skeleton material, thereby realizing the fusion of the electrolyte and electrode interface through the in situ polymerization mechanism, and forming a stable interface in the electrolyte, thereby effectively reducing the interfacial impedance of the electrolyte and improving the performance of the battery.

[0091] In one embodiment, the monomer includes at least one of polyethylene glycol acrylate and polyvinylene carbonate.

[0092] Specifically, since polyethylene glycol acrylate and polyvinylene carbonate have good interfacial compatibility with metallic lithium, the present application effectively improves the electrochemical performance of the electrolyte by setting the monomer to include at least one of polyethylene glycol acrylate and polyvinylene carbonate.

[0093] In one embodiment, the lithium salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium chloride, and lithium nitrate.

[0094] Specifically, since lithium bis(trifluoromethanesulfonyl)imide has high ionic conductivity and thermal stability, the present application uses lithium bis(trifluoromethanesulfonyl)imide as the lithium salt, thereby effectively improving the charge and discharge efficiency and power density of the battery, and allowing the battery to maintain stable performance in a high temperature environment.

[0095] Among them, since lithium bis(trifluoromethanesulfonyl)imide can also form a stable solid electrolyte interface film on the surface of lithium metal and can form good interface contact with the electrode material, the present application further improves the cycle life and safety of the battery by setting lithium bis(trifluoromethanesulfonyl)imide as the lithium salt.

[0096] In addition, since lithium hexafluorophosphate is the most commonly used lithium salt in lithium-ion battery electrolytes, lithium chloride has high solubility, hygroscopicity and good thermal stability, and lithium nitrate can be used as an additive to lithium-ion battery electrolytes, the present application effectively improves the scope of application of the prepared electrolyte by setting lithium hexafluorophosphate, lithium chloride and lithium nitrate as lithium salts.

[0097] Of course, in other embodiments, the lithium salt may also include two or more of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium chloride and lithium nitrate. Those skilled in the art may make a selection according to actual needs, and this application does not make any specific restrictions here.

[0098] In one embodiment, the initiator includes at least one of azobisisobutyronitrile and benzoyl peroxide.

[0099] Specifically, the embodiment of the present application effectively improves the preparation efficiency of the electrolyte by setting at least one of azobisisobutyronitrile and benzoyl peroxide as an initiator.

[0100] In one embodiment, the mass ratio of the monomer, the lithium salt, and the initiator is 100-300:25-100:0.1-6.

[0101] Specifically, the embodiment of the present application effectively improves the in situ polymerization effect between the polymerization solution and the skeleton material by setting the mass ratio of monomer, lithium salt and initiator to 100-300:25-100:0.1-6, thereby further reducing the interfacial impedance of the electrolyte and improving the performance of the battery.

[0102] S104, preparing the polymer solution and the skeleton material into an electrolyte.

[0103] It should be noted that the embodiment of the present application effectively realizes the interface bonding between the polymer solution and the skeleton material by infiltrating the skeleton material with the polymer solution, that is, through the in situ polymerization mechanism between the polymer solution and the skeleton material, thereby reducing the interface impedance, and the polymer solution can also fill the pores and surface defects of the skeleton material to form a uniform coating, thereby further improving the mechanical strength of the electrolyte.

[0104] Among them, in order to better utilize the in situ polymerization mechanism between the polymerization solution and the skeleton material, the polymerization solution and the skeleton material need to be prepared into an electrolyte under certain temperature and time conditions.

[0105] For example, when the initiator is azobisisobutyronitrile, the skeleton material can be infiltrated with a polymerization solution at a temperature of 60 to 80° C. for more than 1 hour to prepare the polymerization solution and the skeleton material into an electrolyte.

[0106] Of course, when the initiator is benzoyl peroxide or other materials, the embodiment of the present application can be used to infiltrate the skeleton material with a polymerization solution at a temperature of 60 to 80°C for more than 1 hour to prepare the polymerization solution and the skeleton material into an electrolyte; alternatively, the embodiment of the present application can also prepare the electrolyte under other processing temperature and processing time conditions. Those skilled in the art can make a choice according to actual needs, and this application does not make any specific restrictions here.

[0107] According to another embodiment of the present application, a battery is provided, wherein the battery includes an electrolyte prepared by the electrolyte preparation method as described in the embodiment of the present application.

[0108] Specifically, in the embodiment of the present application, at least one of lithium iron phosphate and lithium cobalt oxide is used as the positive electrode of the battery, and at least one of metallic lithium and carbon is used as the negative electrode of the battery; the electrolyte is placed between the positive electrode and the negative electrode; the positive electrode, electrolyte and negative electrode are encapsulated to form a battery, and the battery has good cycle stability and can meet the product usage requirements.

[0109] The present application is further described below with reference to specific embodiments.

[0110] Example 1

[0111] S101, dissolving polyvinylidene fluoride in a solvent formed by mixing tetrahydrofuran and N,N-dimethylformamide, and adding fly ash powder particles to the solvent to form a mixed solution. The mass ratio of tetrahydrofuran to N,N-dimethylformamide is 2:3, the mass fraction of polyvinylidene fluoride in the mixed solution is 10%, the mixing temperature is 50°C, and the mixing time is 4 hours.

[0112] S102, using an electrospinning device to prepare the mixed solution into a first composite film, placing the prepared first composite film into a vacuum oven to remove the solvent in the first composite film, and obtaining Figure 2 The skeleton material shown in the figure has the following characteristics: the spinning voltage is 15 kV, the spinning flow rate is 1.2 ml / h, the distance between the spinning needle and the receiving device is 15 cm, the processing temperature of the oven is 70°C, and the processing time of the oven is 1 hour.

[0113] S103: Mix polyethylene glycol acrylate, lithium bis(trifluoromethanesulfonyl)imide, and azobis(isobutyronitrile) to form a polymerization solution, wherein the mass ratio of polyethylene glycol acrylate, lithium bis(trifluoromethanesulfonyl)imide, and azobis(isobutyronitrile) is 200:120:1.5.

[0114] S104, preparing the polymer solution and the skeleton material into an electrolyte, wherein the processing temperature is 70° C. and the processing time is 6 hours.

[0115] The electrolyte prepared in Example 1 was prepared into a button cell and the button cell was tested. Figure 3 As shown, the button battery prepared by the electrolyte prepared in Example 1 has good cycle stability. For example, the first-cycle discharge specific capacity can be 150.8 mA·h·g-1, and the subsequent discharge specific capacity can be above 153 mA·h·g-1; the first-cycle coulombic efficiency can be 96.83%, and the subsequent coulombic efficiency can be maintained above 96%, thereby effectively meeting the use requirements of battery products.

[0116] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0117] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing an electrolyte, characterized in that: include: adding polymer and industrial solid waste to a solvent to form a mixed solution; preparing the mixed solution into a skeleton material; Mixing monomers, lithium salts, and initiators to form a polymerization solution; The polymer solution and the skeleton material are prepared into an electrolyte.

2. The method for preparing an electrolyte according to claim 1, wherein: The solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran and formic acid; The polymer comprises at least one of polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polyethylene oxide and polyvinyl alcohol; The industrial solid waste includes at least one of slag, fly ash and metakaolin; The mass ratio of the polymer to the industrial solid waste is 5:1 to 1:

30.

3. The method for preparing an electrolyte according to claim 1, wherein: The mass fraction of the polymer in the mixed solution is 8% to 25%.

4. The method for preparing an electrolyte according to claim 1, wherein: The mixing temperature of the polymer and the industrial solid waste is 25 to 60° C.; The mixing time of the polymer and the industrial solid waste is greater than or equal to 10 minutes.

5. The method for preparing an electrolyte according to claim 1, wherein: The mixed solution is prepared into a skeleton material comprising: The mixed solution is prepared into a first composite membrane using an electrospinning device; The solvent in the first composite film is removed to form a skeleton material.

6. The method for preparing an electrolyte according to claim 5, wherein: The spinning voltage of the electrospinning device is 8 to 25 kV; the spinning flow rate of the electrospinning device is 1 to 1.5 ml / h; the distance between the spinning needle of the electrospinning device and the receiving device is 10 to 20 cm; The thickness of the first composite film ranges from 5 to 100 μm; The processing temperature for removing the solvent in the first composite film is 25-70°C.

7. The method for preparing an electrolyte according to claim 1, wherein: The mixed solution is prepared into a skeleton material comprising: coating the mixed solution on a carrier device using a coating process to prepare a second composite film; The solvent in the second composite membrane is removed to form a skeleton material.

8. The method for preparing an electrolyte according to claim 7, wherein: The carrying device includes at least one of a polytetrafluoroethylene plate and a polytetrafluoroethylene disc; The thickness of the second composite film ranges from 5 to 100 μm; The processing temperature for removing the solvent in the second composite film is 25-70°C.

9. The method for preparing an electrolyte according to claim 1, wherein: The monomer includes at least one of polyethylene glycol acrylate and polyvinylene carbonate; The lithium salt comprises at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium chloride and lithium nitrate; The initiator comprises at least one of azobisisobutyronitrile and benzoyl peroxide; The mass ratio of the monomer, the lithium salt and the initiator is 100-300:25-100:0.1-6.

10. A battery, characterized in that: The battery includes an electrolyte prepared by the electrolyte preparation method according to any one of claims 1 to 9.

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